Surface Indicators for Gas Turbine Tolerance Verification

Solution Overview

Problem

Gas turbine engine components often require manual grinding to achieve acceptable manufacturing tolerances due to raised surfaces from wax coverage during casting, which is inefficient and time-consuming.

Innovation Solution

Incorporating surface indicators near the exit surface of cooling circuit components to visually indicate whether the component is within acceptable manufacturing tolerances, allowing for immediate identification of the need for secondary operations like sanding or rejection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual grinding is performed to achieve acceptable manufacturing tolerances, then manufacturing precision is improved, but productivity deteriorates due to the time-consuming nature of the process

Engineering Contradiction:

Improveexit surface toleranceVSAvoidinspection and processing speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

Surface indicators are incorporated into the core during the casting process itself, before the component is removed from the mold. This preliminary action allows tolerance verification to be prepared in advance, eliminating the need for time-consuming post-casting measurements and enabling immediate visual assessment of whether manual grinding is required.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual measurement and inspection methods with a visual indicator system. The surface indicators provide direct visual feedback about tolerance compliance, substituting the need for manual measurement tools and skilled inspection, thereby dramatically improving inspection speed while maintaining precision verification.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If manual inspection and measurement are performed to verify manufacturing tolerances, then measurement precision is improved, but loss of time worsens due to the lengthy inspection process

Engineering Contradiction:

Improvetolerance verification accuracyVSAvoidinspection time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces manual measurement and inspection methods with a visual indicator system. The surface indicators provide direct visual feedback about tolerance compliance, substituting the need for manual measurement tools and skilled inspection, thereby dramatically improving inspection speed while maintaining precision verification.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The surface indicators utilize visual differentiation (such as color or surface texture variations) to indicate different tolerance zones. This allows inspectors to immediately identify whether the exit surface is within acceptable tolerances or requires grinding, eliminating time-consuming measurement processes while maintaining accurate tolerance verification.

Inventive Principle:

Principle #32Color changes

3Manufacturing precision

If the exit surface is ground off by hand to provide flush core exits, then manufacturing precision is improved, but ease of manufacture deteriorates due to the complex secondary operation

Engineering Contradiction:

Improvecore exit flushnessVSAvoidmanufacturing process complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Surface indicators are incorporated into the core during the casting process itself, before the component is removed from the mold. This preliminary action allows tolerance verification to be prepared in advance, eliminating the need for time-consuming post-casting measurements and enabling immediate visual assessment of whether manual grinding is required.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3460216B1Method for determining if a component is within an acceptable manufacturing tolerance using surface indicators

Publication Date: 2021.05.12 RTX CORP

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AI summary

A method for determining whether a component (50) is within an acceptable manufacturing tolerance, comprising the steps of: inspecting the component (50) to determine whether a surface indicator (84) is visible in the component after the component (50) has been manufactured; and determining whether the component (50) is within the acceptable manufacturing tolerance based on a predetermined pattern of the surface indicator (84) that is visible in the component (50).